Abstract: A test rig forhigh-pressurewaterdriven systemswas developed tomeet the requirements of the performance test on water pumps, motors and valves, as well as synchronized tests on water cylinders. A high-pressurewateraxialpiston pumpwith an outputcapacity of25. 3mL/minwas tested on the test rig. The test result shows that the response time of the pump is 1. 1 ms, but its volumetric efficiency decreases obviously with an increase in pressure at speed less than 1 000 r/min. It is concluded that reducing leakage is one of the key issues to improve the performances ofhigh-pressure water pumps.